The author's attitude toward genetically-modified foods is _________.

A．are superior to naturally grown foods
B．might prove to be risky to human health
C．are going to replace naturally grown foods
D．can solve the food problems in developing countries

A．they can use marks to judge students
B．they can control students' behavior
C．they may judge students from their own likes and dislikes
D．their words are usually respected by the children